The Earp Vendetta Ride was a search by Deputy U.S. Marshal Wyatt Earp, leading a federal posse, for outlaw Cowboys they believed had ambushed and maimed Virgil Earp and killed Morgan Earp. The Earp brothers had been attacked in retaliation for the deaths of three Cowboys in the Gunfight at the O.K. Corral on October 26, 1881. From March 20 to April 15, 1882, the federal posse searched southeast Cochise County, Arizona Territory for suspects in both Virgil's and Morgan's attacks.